TLD means Top Level Domain, and it’s the suffix of a domain name.
A domain name is built with three parts, each one separated by a dot. The subdomain is on the left side. The second-level domain (SLD), brand, or a name that states the kind of business you have, comes in the middle. And the top-level domain (TLD) is at the end (.com, gov, .org, .net, .de).
Example: www.speaking-easy.com, “www” is the subdomain, “speaking-easy” the SLD, and “.com”, the TLD.